1. doc.: 15-06-0032-00-0005 Submission 2006-01-16 S. Max, G.R. HiertzSlide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Challeges in (WPAN) Mesh Networks] Date Submitted: [16 January, 2006] Source: [Sebastian Max, Guido R. Hiertz] Company [Philips Research Laboratories Aachen, ComNets, RWTH Aachen University] Address [Kopernikusstr. 16, 52074 Aachen, Federal Republic of Germany] Voice:[+49-241-80-25-82-9], FAX: [+49-241-80-22-24-2], E-Mail:[smx@comnets.rwth-aachen.de] Re: [] Abstract:[To aid discussion.] Purpose:[This document describes some problems inherent to mesh networks, some of them are especially severe in mesh WPAN networks. It should aid the discussion about different MAC schemes and which problems have to be solved in an efficient mesh WPAN MAC.] Notice:This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release:The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15.

2. doc.: 15-06-0032-00-0005 Submission 2006-01-16 S. Max, G.R. HiertzSlide 2 Challenges in (WPAN) Mesh Networks Sebastian Max, Guido R. Hiertz Philips Research Laboratories & Chair of Communication Networks, RWTH Aachen Aachen, Germany

3. doc.: 15-06-0032-00-0005 Submission 2006-01-16 S. Max, G.R. HiertzSlide 3 A User’s Perspective: Applications Summary of CFA answers & analysis –High rate Home multimedia PC cable replacement Connect handheld devices Indoor location based services –Low rate Home/office control Security systems Medical support Industrial monitoring Logistics / tracking

4. doc.: 15-06-0032-00-0005 Submission 2006-01-16 S. Max, G.R. HiertzSlide 4 Technical Requirements: High Rate Assumptions –Low mobility –Small to medium network size, mesh & tree topology Requirement –Easy setup, usage  “self-organized” –High reliability –End-to-end throughput measured in Mb/s –End-to-end delay measured in ms, strict bounds Mesh benefit compared to non-mesh –Coverage extension –Route redundancy –High throughput over larger distance

5. doc.: 15-06-0032-00-0005 Submission 2006-01-16 S. Max, G.R. HiertzSlide 5 Technical Requirements: Low Rate Assumptions –Relatively low throughput (measured in kb/s) –Delay below 250ms –Low … medium mobility –Large networks, mainly mesh topology Requirements –Security & privacy –Low complexity –High reliablity Mesh benefit compared to non-mesh –Coverage extension –Route redundancy –Power saving

6. doc.: 15-06-0032-00-0005 Submission 2006-01-16 S. Max, G.R. HiertzSlide 6 Challenges Routing Addressing Power control Topology control Link adaptation Single point of failure Route redundancy High rate –Maintain high bit rate over several hops –Very delay sensitive –Distinct behavior of mains- and battery powered devices Low rate –Very efficient power saving –Scalability in network size / density and hop number

7. doc.: 15-06-0032-00-0005 Submission 2006-01-16 S. Max, G.R. HiertzSlide 7 Problems inherent to WPAN-Mesh Limited horizon Power consumption Interference Awareness Route fairness Reliability

8. doc.: 15-06-0032-00-0005 Submission 2006-01-16 S. Max, G.R. HiertzSlide 8 Limited Horizon Local knowledge –Limited by Rx range Extended impact –Interference –Congestion  Consequence aware MAC

9. doc.: 15-06-0032-00-0005 Submission 2006-01-16 S. Max, G.R. HiertzSlide 9 Power Consumption High demands for relay nodes Power save vs. relay job Transmission power control  Power aware MAC

10. doc.: 15-06-0032-00-0005 Submission 2006-01-16 S. Max, G.R. HiertzSlide 10 Interference Awareness Mutual interference System capacity shared Walls attenuate interference Capacity increase possible  Interference aware MAC

11. doc.: 15-06-0032-00-0005 Submission 2006-01-16 S. Max, G.R. HiertzSlide 11 Route Fairness Short versus long route –Punishment of multihop routes –Cumulative bandwith of several hops –Retransmission of lost packets

12. doc.: 15-06-0032-00-0005 Submission 2006-01-16 S. Max, G.R. HiertzSlide 12 Reliability Avoid single point of failure –Routing –Transmit control (channel, time, power, …)

13. doc.: 15-06-0032-00-0005 Submission 2006-01-16 S. Max, G.R. HiertzSlide 13 Mahalo for your attention! Questions? Discussion!